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There's no question that Europe has the oldest and grandest cathedrals in the known universe. However, the U.S. is no slouch when it comes to cathedrals. From breathtaking architecture to history lessons, the 10 cathedrals listed below are worth a trip.

St Louis: The Byzantine and Romanesque triumph of the Cathedral Basilica of Saint Louis is best known for having one of the largest mosaic collections in the western hemisphere. Composed of more than 41 million pieces of tile in 8,000 colors, the mosaics cover more than 83,000 square feet. Completed in 1914, the cathedral was designated a basilica by Pope John Paul II in 1997, who later visited in 1999. The museum in the basement is dedicated to the design and application of the mosaics as well as a crypt and artifacts from the Cathedral, including the original Kilgen organ console. The Cathedral is open daily for masses and self-guided tours.

Philadelphia: The Cathedral of Sts. Peter & Paul is the largest brownstone structure in Philadelphia and one of its most iconic structures. Large enough to hold 2,000 worshippers, it was built from 1846 to 1864, modeled after Rome's Lombard Church of St. Charles (San Carlo al Corso), with an Italian Renaissance style Palladian façade and aqua oxidized-copper dome. Psst: rumor has it that Pope Francis might visit here in September 2015 when the World Meeting of Families comes to Philadelphia. It will soon be possible to double one's cathedral experience here; a large Mormon Temple is being erected next door, estimated to be completed in 2016.

Dallas: Built between 1898 and 1902, constructed using local brick, the Cathedral Santuario de Guadalupe is one of Dallas' most notable 20th century structures. The massive Gothic Revival structure accommodates an average of 11,200 (!) people each Sunday; the second largest Catholic Church membership in the United States. Its 20-story bell tower (a recent addition that was part of the Cathedral's original plans, but never built) contains a 49-bell carillon. Though the overwhelming majority of parishioners are Spanish speakers, ministries are conducted in English as well as Spanish.

Baltimore: America's first Roman Catholic cathedral, the Basilica of the National Shrine of the Assumption of the Blessed Virgin Mary was built between 1806 and 1821 in Baltimore's Mount Vernon neighborhood, a few blocks from the Inner Harbor. It was designed in neoclassical-style by Benjamin Henry Latrobe, America's first professionally trained architect. The Basilica has enjoyed an enviable list of famous visitors, including Pope John Paul II, Mother Teresa, and Ecumenical Patriarch Bartholomew I of Constantinople, among many other saints (and potential saints). The Basilica is listed on the National Register of Historic Places and was made a National Historic Landmark in 1971.

New York City: Second in size only to St. Peter's Basilica in Vatican City, the Cathedral Church of St. John the Divine occupies an entire city block in Manhattan's Morningside Heights neighborhood. It's said to be tall enough to fit the Statue of Liberty inside and can hold up to 5,000 people. Ground was broken for the Cathedral in 1892 and due to a number of set backs (the two World Wars) and several fires, most recently in 2001, it's still unfinished, earning it the nickname "St. John the Unfinished." The limestone-granite structure, after some design changes, has evolved into its current French Gothic style, including the Great Rose Window, the largest stained-glass window in the U.S., with more than 10,000 pieces of colored glass.

Washington, D.C: The neo-Gothic Washington National Cathedral (aka the Cathedral Church of Saint Peter and Saint Paul) is the most stately church in a city with a heck of a lot of churches. It has staged 21 presidential funerals (from William McKinley in 1901 to Gerald Ford in 2007) as well as serving as the final resting place for Helen Keller and Woodrow Wilson, among others. It took 83 years to build the 517-foot long building (officially completed in 1990) composed of Indiana limestone arches, flying buttresses and stained glass windows. Perhaps its most unusual fixture is the relatively recent addition of a Darth Vader sculpture at the top of the west tower.

St Paul: The striking Cathedral of Saint Paul is made all the more grander by its location, sitting at the top of Cathedral Hill, overlooking downtown St. Paul. Opened in 1915 and still the third largest church in the U.S., the Cathedral is crowned by a distinctive copper-clad dome 76 feet in diameter. Its design is partly modeled on the Sacre-Coeur basilica in Paris and contains many French Renaissance and Classical themes. It was added to the National Register of Historic Places in 1974.

New Orleans: The Cathedral-Basilica of St. Louis King of Franceis the oldest continually used Catholic cathedral in the country. The current structure was built in 1794 (replacing its burned down predecessor built in 1720) and expanded and rebuilt to its current state in 1849. Located on Jackson Square, facing the Mississippi River, the fairytale yet comparatively simple exterior includes a central clock and three spires, one acting as a bell tower. Inside is an Italian organ from 1825. Famous visitors include Andrew Jackson and Pope John Paul II. The Cathedral is said to be haunted by a former priest buried within the church.

San Francisco: With twin bells towers at the front and a massive circular stained glass window above the entrance, Grace Cathedral is reminiscent of Paris' Notre Dame Cathedral. Founded in 1849 and located in San Francisco's Nob Hill, the Cathedral is notable for its elaborate stained glass windows depicting various biblical stories and the stunning window illustrating the Twenty-Third Psalm ("The Lord is my shepherd, I shall not want"). Grace Cathedral is also known for its indoor and outdoor Labyrinth, a design tradition started at France's Chartres Cathedral (1220), for people to walk as they meditate and focus on God's healing power. Famous visitors have included Dr. Martin Luther King, Jr., Archbishop Desmond Tutu, Jane Goodall, Isabel Allende, Carlos Santana, Sandra Day O'Connor, and the Dalai Lama.

Colorado Springs: Constructed in 1962 with aluminum, glass and steel, and featuring 17 linear spires, the 150-foot tall modernist United States Air Force Academy Cadet Chapel was awarded the American Institute of Architects' National Twenty-Five Year Award in 1996. It's open to all faiths, hosting separate chapels for Protestant, Catholic, Jewish, and Buddhist faiths and an additional all-faiths room for Muslim cadets and others. With two main levels (the Protestant nave on the upper level and the other chapels below), Chapel services can be held simultaneously without interfering with one another.